Control of VCSEL emission for better high-speed performance
View Patent ↗A device includes a VCSEL, an optical fiber, and a lens. The VCSEL generates optical light signals having a spatial emission pattern based around an axis of emission. Light signals emitted from the VCSEL substantially along or near the axis of emission are known as high speed modulation patterns. Light signals emitted at angles away from the axis of emission are known as slow speed modulation patterns. Slow speed modulation patterns become slower as the angle between the emitted light signals and the axis of emission increase. The lens is selectively positioned between the VCSEL and the optical fiber for focusing the high speed modulation patterns of the light signals on the optical fiber, and the lens substantially does not focus the slow speed modulation patterns of the light signals on the optical fiber.
1. An optoelectronic device consisting of:
only one vertical cavity surface emitting laser for generating optical light signals having a spatial emission pattern based around an axis of emission, light signals emitted from the only one vertical cavity surface emitting laser substantially along or near the axis of emission are known as high speed modulation patterns, and light signals emitted at angles away from the axis of emission are known as slow speed modulation patterns, and wherein the slow speed modulation patterns of the light signals become slower as the angle between the emitted light signals and the axis of emission is increased, and wherein the only one vertical cavity surface emitting laser operates at speeds above two and one-half Gigabits per second;
only one element having only one aperture, the only one aperture sized so as to allow the high speed modulation patterns of the light signals to pass therethrough, and the only one aperture sized so as to substantially prevent the slow speed modulation patterns of the light signals from passing therethrough;
only one optical fiber; and
only one lens positioned between the only one vertical cavity surface emitting laser and the only one optical fiber, the only one lens positioned in the only one aperture of the only one element, and wherein the only one lens focuses the high speed modulation patterns of the light signals on the only one optical fiber, and wherein
the only one lens, when viewed from a perspective substantially perpendicular to the axis of emission of the only one vertical cavity surface emitting laser, has a shape of an ellipse, and wherein
the only one lens is separated from the only one optical fiber by a gap, and wherein
the only one element is separated from the only one optical fiber by the gap, and wherein
the only one element is positioned between the only one vertical cavity surface emitting laser and the only one optical fiber, and wherein
the only one optical fiber includes a core surrounded by cladding, and wherein the high speed modulation patterns of the light signals are focused on the core.
2. An optoelectronic device according to claim 1 wherein the only one element is substantially opaque to slow speed modulation patterns of the light signals.
3. An optoelectronic device according to claim 1 wherein the only one element is made of a material that is transparent and diffuses slow speed modulation patterns of the light signals away from the only one optical fiber.